Ordinary vegetables, especially leafy greens, lose some nutrients and their calorie index increases after being stir-fried in oil. For instance, vegetables like spinach and rape have a high oil absorption capacity, so eating these oil-rich vegetables leads to a higher calorie intake.
Some vegetables can be eaten raw, such as carrots, cucumbers, tomatoes, bell peppers, lettuce, bok choy, cabbage, chili peppers, onions, and celery. Without being cooked in oil, these vegetables are low in calories, their vitamin content is preserved, and the nutrients they provide can help break down fats after being converted into carbohydrates.
Methods for eating vegetables raw include drinking fresh homemade vegetable juice or eating them in a cold salad. It's best not to peel cucumbers when eating them raw, and tomatoes should not be blanched and peeled, as blanching alters the vitamin C content and makes them taste sour. For raw lettuce, it is best to peel, wash, and then briefly scald it in boiling water before marinating it with seasonings for 1-2 hours before eating.